How can I get it through to my partner that she can't afford an unpaid internship?

I temped for many years, and the one year when I had a class on Wednesdays, I was rarely in work. Yes, temp agencies are flexible, but it's the luck of the draw whether they can find you a gig that week that doesn't require you to work Wednesdays. If it had been any other day of the week, she might not be having as much trouble. I also had one company cut my hours to 5 per week, and they had to be on a Wednesday afternoon; they were effectively monopolizing my time by demanding this as I never got one single other job as long as I was booked for that one. I do think you have a right to question all of this. A number of posters have raised details that don't seem to hang together. I think either she doesn't want to work, or you are trying to get us to tell you she doesn't want to work, and I'm not sure which.

For a sense of scale, my wife and I don't make a ton (we are both in academia as non-PhD research staff), and our "whatever money", where we're not accountable to each other, is on the order of 8% of our NET income (after taxes, insurance, retirement, HSAs). Total. That's for everything from individual hobbies to individual dining out to clothes to haircuts. Basically, it's what's left over after all of our joint expenses. It works well for us. You two should take a long look at your joint expenses and see where additional income can be found (her part) and where fat can be trimmed (your part). If you're both unhappy, congratulations: you've made a successful compromise. That's my $0.02, anyway.

I don't think it's selfish at all to expect your partner to contribute. My partner's ex did not contribute (she worked freelance in a field with really small prospects and viewed her meager earnings as pocket change) and it was a huge issue for him. One of the things he likes about me is that I am practical about money. We did sit down and have that one practical but not very romantic conversation about it, and it helped a lot for both of us to have solid facts. When we looked at necessary expenses (rent, car costs for him, bus pass for me and so on) we worked out how much that would cost per month and then anything we earned on top of that was extra. It wasn't about judgements or about who makes more or less or whose hobby is this or that. It was strictly 'it will take X to keep the ship running, so that's Y for each of us.' In my case, I am spending slightly more with him than I did without him because he has a bigger apartment, a car, a dishwasher and some other stuff I didn't have before. But he also has more savings and more earning potential down the road, and he is happy to contribute more this summer since my summer job fell through (I am a teacher and have no summer income) or if I took time off for a baby or something. The important thing is that the conversation was not about judgements. It was about how each of us is partaking of shared resources that equal this many dollars, so Y is his share and Z is my share and it's fair for both of us.

My question is this... It seems like your partner running out of money would have been something foreseeable, like you could have predicted it would happen. Did you have a contingency plan? I suggest you cut the baby in half by agreeing to ditch the collections and cut the food and alcohol budget for a few months to allow her to seek work if she can cajole her internship into having her day off be a floating one. That way, she doesn't have to place any restrictions on days when looking for work and can do the internship on a day off, basically relegating it to the role of a hobby, which is exactly what she says your eBaying is, which you will then be able to resume during YOUR free time once she finds the job and starts bringing in money. I'd also be REALLY curious to see her side of this issue. I've occasionally thought of bringing relationship issues here, but I've always thought the thing to do would be to present either a joint statement, or to present both sides. Maybe we could get a better idea of how to help you if you gave her a chance to write about the situation as she sees it and send it to an admin.

I would really like to hear what she is doing the other 6 days of the week. The story as is just isn't making sense to me

My partner refuses to consider giving up her unpaid internship in order to find a job and is furious with me for suggesting that she should. I'm confused by this language. The rest of your post doesn't make it at all clear that she would have to give up her internship to take a casual job. Basically (as I understand it) you are suggesting she claim complete availability in order to land a second job, and then work the internship around it, and you seem to think that's perfectly possible. It certainly sounds feasible enough. But is there some sense in which that's not the true picture? Assuming that she can do both, it may also be true that getting a job in retail or food is just not that easy where you are, and that the Wednesday thing may not be the whole reason she's not getting a job. It does seem kind of odd that she is getting interviews but not hired, but right now people have their pick when it comes to hiring for even the crummiest jobs.

This is just conjecture, but the OP mentioned the one day a week thing as his girlfriend "keeping up" her internship, which makes it sound like she might have been working more before the pressing need for more money necessitated cutting back on her hours.

There is a possibility that I'd like to mention, which I'm not sure about, but you would be. Does this smell like testing behavior? You mentioned that the EBay habit features prominently in your arguments, could this be an elaborate way in which she is trying to figure out if you would give it, nice beer, and everything else up for her? Good partners are very often totally worth these things, but partners who push a relationship towards them to see if it will survive are so very much not good partners.

My first summer off during my undergrad, I sent out dozens of resumes everywhere. Places were hiring. And I had previous cafe/cashier experience. But no one wanted to hire me because I would only be around for four months before leaving again for school. She might need to gloss over the fact that she'll be going back to school. Or take the part about the master's degree off of the resume. Or say that she wants to continue working part time after she goes back to school. It's a tricky situation - of course you want to be honest - but this might be why she isn't getting hired. Something to consider.